1. Problem: Find the number of things which coincide with one another. 2. The question asks: "The things which coincide with one another are?" with options a)0 b)1 c)2 d)3. 3. Explanation: When two things coincide, they overlap exactly. The number of things that coincide with one another is 1 because coincidence means one single point or object. 4. Therefore, the answer is b) 1. Final answer: 1